1. Field of the Prior Art
The present invention relates to a snap-action heat responsive device incorporating a bimetallic strip which is adapted for use with a thermostat, a temperature-protecting device or the like.
2. Description of the Prior Art
A conventional type of heat responsive device employing a bimetallic strip is previously disclosed in Japanese Patent Publication No. 32945/1979 and Japanese Utility Model Laid-open No. 160445/1983. In general, the heat responsive device of the prior art includes a bimetallic strip consisting of two strips each having a concave shape in cross section. Although it is relatively easy to work a large-sized bimetallic strip having such a concave shape, there is a problem in that, as a bimetallic strip to be worked is reduced in size, it becomes difficult to form a concave shape with high precision. This may lead to a problem in that the prior-art thermostat employing a bimetallic strip having a concave cross-sectional shape is unavoidably increased in size due to limitations imposed on its structure.
In addition, it is difficult to apply such a bimetallic strip having a concave cross-sectional shape to a heat responsive device of the type used as a small-sized current limiter or the like which is attached, for example, to a printed circuit board for the purpose of handling an electric current of about one ampere.